Method: EventMachine::Iterator#initialize

Defined in:
lib/em/iterator.rb

#initialize(list, concurrency = 1) ⇒ Iterator

Create a new parallel async iterator with specified concurrency.

i = EM::Iterator.new(1..100, 10)

will create an iterator over the range that processes 10 items at a time. Iteration is started via #each, #map or #inject

The list may either be an array-like object, or a proc that returns a new object to be processed each time it is called. If a proc is used, it must return EventMachine::Iterator::Stop to signal the end of the iterations.

Raises:

  • (ArgumentError) 


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# File 'lib/em/iterator.rb', line 56

def initialize(list, concurrency = 1)
  raise ArgumentError, 'concurrency must be bigger than zero' unless (concurrency > 0)
  if list.respond_to?(:call)
    @list = nil
    @list_proc = list
  elsif list.respond_to?(:to_a)
    @list = list.to_a.dup
    @list_proc = nil
  else
    raise ArgumentError, 'argument must be a proc or an array'
  end
  @concurrency = concurrency

  @started = false
  @ended = false
end